The present invention relates to a system and method for altering the time frame of date dependent information.
The need to alter the time frame of date dependent information has become apparent with the need to achieve Year 2000 compliance. A number of proposals have been made to deal with the way in which Year 2000 compliance can be achieved and one proposal is set out in U.S. Pat. No. 5,600,836 where it is proposed that date data in local time (real time) should be converted to zone time in a time change interface so that all of the dates are in one century. Once the dates are in zone time the computer program application processes the date data in zone time instead of local time and after processing the data is reconverted by a time change interface from zone time to local time. In this way, a user is presented with information in local time and can enter data in local time but the computer operates in the zone time in order to avoid problems which arise if the systems are not Year 2000 compliant.
A particular problem arises if one is looking at a computer system which has a very large database containing date dependent information. In U.S. Pat. No. 5,600,836, it is proposed that when there is a database present, the date data in the database is converted in advance to zone time. While this is technically possible, it is not a practical proposition when dealing with very large databases in view of the fact that the computer system has to be taken off-line while the database is being converted and the computer may be off-line for a considerable period of time, even days. For most organizations having large databases this is not feasible and a different solution has to be used.
Another approach to the problem of Year 2000 compliance has been to maintain the database information unaltered but to re-write the application programs to take account of Year 2000 problems. This is an extremely expensive and time consuming operation and is not thought to be an appropriate solution.